Thesis from Leicester Polytechnic
Mr C Polonski and Messrs GEC Gas Turbines for loan of equipment
Messrs Rolls Royce for the provision of equipmentThe turbocharging of automotive sized two-stroke engines presents
a problem to the designer due to the large range of loads and speeds
met in service. A mechanically driven blower is usually required to
provide a positive pressure drop across the engine at all times, thus
providing adequate air for scavenging.
The aim of this investigation is to consider a. combination of the
two-stroke cycle engine, turbocharger and auxiliary combustion chamber
as a prime mover system with a satisfactory torque characteristic and
control system. The auxiliary combustion chamber is used for independent
control of the turbocharger.
To this end various component combinations are described and
assessed. Turbochargers of different builds and frame sizes havebeen
examined to assess the effects of turbocharger matching.
Computerised processing for data acquisition and control has been
used.
Theoretical work, progressing simultaneously with the experimental
programme, has permitted the development of simple computer programs
to predict system performance to a good degree of accuracy. The
programs are detailed in the appendix.
Experimental results have been presented graphically and compared
with those predicted by the computer programs. The work has been
extended, by computer techni~ues, to investigate the effects of charge
cooling, heat exchange, and torque 'tailoring' by the control of
engine boost levels.
The Diesel Gas Turbine is shown to provide a feasible prime
mover system. Significant improvements of power output and torque
characteristic have been achieved within constraints of thermal and
mechanical loading. The system incurs penalties in specific fuel
consumption at low speeds but these are offset, to some extent, by
improvements at high speed. The improved torque characteristics;
would permit the use of a simpler transmission system, together with
the removal of the scavenge blower.Leicestershire County Council and the Directorate of Leicester Polytechni
